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    <title>Document</title>
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<script>
    function noRepeatArray(arr){
        let arr1=[];
        for(let i=0;i<arr.length;i++){
            if(arr1.indexOf(arr[i])==-1){
                arr1.push(arr[i]);
            }
        }
        return arr1;
    }
    let arr=[3,3,1,5,1,2]
    console.log(noRepeatArray(arr));
</script>